title: Redox-responsive organometallic foldamers from ferrocene amino acid: solid-phase synthesis, secondary structure and mixed-valence properties.
abstract: Oligoferrocenes Fmoc-Fca(n)-OMe (n=3-5) are assembled in a stepwise precise manner from Fmoc-protected ferrocene amino acid Fmoc-Fca-OH (H-Fca-OH = 1-amino-1'-ferrocene carboxylic acid; Fmoc = 9-fluorenylmethyloxycarbonyl) via amide bonds on solid supports by sequential Fmoc deprotection, acid activation and coupling steps. The resulting well-defined oligomers form ordered zigzag structures in THF solution with characteristic hydrogen bonding patterns. Electrochemical experiments reveal sequential oxidations of the individual ferrocene units in these peptides giving mixed-valent cations. Optical intervalence electron transfer is detected by intervalence transitions in the near-IR.
authors.affiliation: Johannes Gutenberg-University of Mainz, Duesbergweg 10-14, 55128, Mainz, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Siebler
authors.forename: Christoph
authors.initials: C
authors.lastname: Förster
authors.forename: Katja
authors.initials: K
authors.lastname: Heinze
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D004151:Dipeptides / Q000737:chemistry; D005296:Ferrous Compounds / Q000737:chemistry*; D005449:Fluorenes / Q000737:chemistry; D000075163:Metallocenes; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D057786:Peptidomimetics / Q000138:chemical synthesis* / Q000737:chemistry*; D017433:Protein Structure, Secondary; D012996:Solutions; D013057:Spectrum Analysis
chemical_list: C496789:9-fluorenylmethoxycarbonyl; D000596:Amino Acids; D004151:Dipeptides; D005296:Ferrous Compounds; D005449:Fluorenes; D000075163:Metallocenes; D009942:Organometallic Compounds; D057786:Peptidomimetics; D012996:Solutions; C004998:ferrocene